| Abstract: | Of 103 patients with isolated systolic hypertension, 71 were treated with diuretics and another 32 with low-sodium diet. In the 71 who were treated with diuretics, body weight decreased from 69.48 ± 1.47 to 68.60 ± 1.45 kg (p < 0.0005) and systolic blood pressure from 178 ± 2 to 152 ± 2 mm Hg (p < 0.0005). Plasma renin activity increased from 1.78 ± 0.30 to 7.32 ± 1.78 ng/ml per hour (p < 0.005) and urinary aldosterone from 10 ± 1 to 23 ± 4 μg per 24 hours (p < 0.005). The greatest decrease in systolic blood pressure occurred in patients in the low-renin group (?32 ± 2 mm Hg), whereas it decreased by 24 ± 2 mm Hg (p < 0.04) in the normal-renin group; however, blood pressure did not change significantly in the high-renin group. In the 32 patients who were treated with low-sodium diet, the 24-hour urinary sodium excretion decreased from 143 ± 10 to 48 ± 5 meq (p < 0.005), body weight decreased from 71.18 ± 2.50 to 70.17 ± 2.47 kg (p < 0.005), systolic blood pressure decreased from 174 ± 2 to 156 ± 3 mm Hg (p < 0.0005), and diastolic blood pressure decreased from 90 ± 1 to 87 ± 1 mm Hg (p < 0.01). Plasma renin activity increased from 2.25 ± 0.33 to 4.27 ± 0.43 ng/ml per hour (p < 0.005) and urinary aldosterone from 9 ± 1 to 15 ± 2 μg per 24 hours (p < 0.005). The decrease in the systolic blood pressure was related to the pretreatment 24-hour urinary sodium excretion (r = 0.40, p < 0.05). The smallest decrease in systolic blood pressure occurred in the patients with high renin values (?1 ± 9 mm Hg, n = 5), whereas the decrease in systolic blood pressure in the low-renin (n = 12) and normal-renin groups (n = 15) was similar, ?22 ± 2 mm Hg and ?21 ± 3 mm Hg, respectively (p < 0.005 compared with the high-renin group). These results indicate that both diuretic therapy and low-sodium diet are effective antihypertensive means in most patients with isolated systolic hypertension and low or normal plasma renin activity. |
